The present invention generally relates to vehicle lamp assemblies, and more particularly relates to map lamp assemblies for implementation in rearview mirror assemblies.
Semiconductor optical radiation emitters are semiconductor devices that emit optical radiation in response to electrical excitation. Examples of semiconductor optical radiation emitters include light emitting diodes (LEDs), light emitting polymers (LEPs), organic light emitting devices (OLEDs, polymer light emitting devices (PLEDs), and others devices.
In some applications, multi-color combinations of pluralities of visibly colored LEDs are being used as the source of projected white light for illumination in binary-complementary and ternary RGB illuminators. Such illuminators are useful as vehicle or aircraft maplights, for example, or as vehicle or aircraft reading or courtesy lights, cargo lights, license plate illuminators, backup lights, and exterior mirror puddle lights. Other pertinent uses include portable flashlights and other illuminator applications where rugged, compact, lightweight, high efficiency, long-life, low voltage sources of white illumination are needed. Phosphor-enhanced “white” LEDs may also be used in some of these instances as illuminators.
With the advent of light emitting diode (LED) illuminator assemblies capable of emitting white light, LEDs have now been implemented in vehicle lamp assemblies. An example of a rearview mirror assembly incorporating LED map lamps is disclosed in commonly assigned U.S. Pat. No. 5,803,579. One form of LED developed by the assignee for use in vehicle lamp assemblies is disclosed in U.S. Pat. Nos. 6,335,548 and 6,441,943. As disclosed in U.S. Pat. No. 6,441,943, the LEDs disclosed in U.S. Pat. No. 6,335,548 may be placed in mirror assemblies and connected to heat sinks within those mirror assemblies. In another example of the use of LEDs in a mirror assembly, a plurality of blue-green and amber LEDs is positioned in two separate groups for emitting light onto the lap area of the driver and front passenger, with each of the two groups of LEDs providing illumination to a separate area.
The use of LEDs in rearview assemblies can be highly effective and advantageous over assemblies incorporating incandescent bulbs for a number of reasons. Reduced power consumption, reduced heat dissipation, and lower cost are some of the reasons that LEDs can be an attractive alternative to incandescent bulbs in vehicle rearview assemblies. However, while the use of LEDs in rearview assemblies can provide benefits, it is often desirable to provide adequate illumination for multiple separate areas, such as the lap area of a driver and the lap area of a front passenger, while at the same time reducing the component count and associated cost required for construction of such rearview mirror assemblies.